Description of the instrument

Infrared spectrophotometry is an analytical technique useful for determining, identifying or confirming the structure of known and unknown products. An infrared spectrum makes it possible to easily highlight the presence of certain functional groups, and can serve as a “spectroscopic identity card” for a molecule or a material.

The Smart iTR is an ATR (Single Reflexion Attenuated Total Reflectance) accessory. The principle consists in bringing a crystal (ZnSe or diamond) into contact with the sample to be analyzed. The IR beam propagates in the crystal; if the refractive index of the crystal is higher than that of the sample, then the beam undergoes total reflections beyond a certain angle of incidence at the sample / crystal interface with the exception of a wave , called evanescent wave which emerges from the crystal and is absorbed by the sample. It is this evanescent wave which is responsible for the IR spectrum observed. The penetration depth is around 1 to 2 micrometers, which therefore provides surface information. This is particularly interesting for the analysis of pure samples (without dilution in a KBr matrix) since the risk of seeing the peaks saturate is very low. In addition, at low energies, the resolution is generally better than for a “classical” spectrum in transmission. ATR is a very reproducible technique which is particularly suitable for quantitative analysis and which is particularly suitable for the analysis of pure powders, and especially liquids, pasty products and films. Measurements can be made by applying controlled pressure.

Model : Thermo Scientific, Nicolet 6700 / Smart iTR
Room : PK-2375